A typical welding station includes a welding table and clamps or fixtures for holding workpieces in a fixed location with respect to the welding table. Once the position of the workpiece or workpieces are so fixed, a welding operation can be performed thereon. When similar weld operations are performed on a large number of workpieces or parts, a special purpose clamp or fixture can be constructed for the particular parts and welding operation. When smaller quantity operations are required, such custom clamping fixtures are impractical. Thus, where a multitude of different, small piece count welding operations are to be performed, a low cost clamping system or device is desirable which can be easily adapted to different clamping tasks. Common C-clamps are adaptable to many different applications, but are limited to locations near the edge of a welding table. Acorn tables containing a grid array of vertical holes provide for variable clamping configurations when used with commercially available clamps. Clamps may be selectively mounted to an acorn table using one or more of the holes to achieve many different workpiece orientations and positions. Unlike C-clamps used with ordinary workbenches, acorn tables and associated clamps allow the interior of the table to be used for clamping. However, acorn tables are costly. In addition, existing clamping arrangements such as custom fixture tables and acorn tables do not allow for ease of storage. In many manufacturing situations, once a certain workpiece clamping setup has been achieved, it is desirable to store the setup until another batch of a particular part is to be run again. Custom clamping fixtures, if permanently mounted to a welding table, are often unwieldy or clumsy, due to the added protrusion from an otherwise flat table, as well as to the added weight. This creates problems in storing a clamping setup. Similarly, acorn tables with one or more clamps fixed in specific locations can be stored, but the clamps protruding from the top and perhaps the bottom of the table require extra storage space and are sometimes subjected to damage during movement. Moreover, the clamps attached to such stored acorn tables are unavailable for use with other tables or fixtures. Consequently, there remains a need for a clamping apparatus or system which provides easily reconfigurable, cost effective clamping of welding operation workpieces to a welding table or other work surface which can be easily stored while preserving specific clamping configurations, which occupies only slightly more storage space than the table itself, and which allows individual clamps to be used apart from the clamping configuration.
In accordance with the present invention, there is provided a shoe clamp for holding a workpiece in a fixed location for the performance of a welding operation. More particularly, and in accordance with the principal aspect of the invention, there is provided a clamping apparatus including a clamp with a foot removably engaging a shoe which itself is mounted to a welding table or other work surface. In this regard, the shoe may be positioned in a specific location on a welding table alone or in combination with other clamps, to provide a specific clamping setup or configuration. Such a configuration can achieve the functional equivalence of a special purpose fixture because the shoe or shoes may be located anywhere on the work surface. With one or more such shoes attached to a welding table, the associated clamps may be slidingly engaged in corresponding shoes and adjusted so as to clamp one or more workpieces being welded. When a different setup is needed, such as for a different part of welding operation, the clamps may be removed or slidingly disengaged from the shoes and the table. The welding table, complete with attached shoes, can be stored. In this regard, the clamping configuration is saved because the shoes are precisely located on the welding table. Furthermore, the table is easily stored because it does not include the lengthy protrusions of the clamps, nor the weight of the clamps. This invention also allows the clamps to be utilized apart from the stored welding table. The clamps can be engaged with other shoes mounted onto other tables or fixtures. The shoes themselves are inexpensive to construct, add little weight to the welding tables, and are themselves reusable. The shoes, moreover, can be manufactured from a weldable material, making them easily attachable to a welding table or even to a workpiece by welding. A user can thus have many inexpensive, reconfigurable shoes mounted on various fixtures or welding tables, and a relatively small number of clamps with feet for engaging the shoes.
In accordance with another aspect of the invention, there is provided a clamp foot which itself can be welded to a welding table. This allows attachment of a clamp to a welding work surface for use in a given location, even in the center of a welding table, and where no holes are provided in the table. Such a clamp foot can be fashioned to engage with a shoe as described above if desired, and to alternatively be weldable to a welding work surface. This allows a user to, for example, utilize a shoe clamp for high quantity clamping configurations, and a quick foot clamping setup for one-time or small volume jobs. Where a foot or shoe has been welded to a welding table surface, the weld material can be ground away from the shoe or foot. The foot or shoe is then reusable.
In accordance with still another aspect of the present invention, the foot can be removably mountable to the base of the clamp. In this regard, the foot can be easily attached to any of a number of commercially available industrial clamps having standard base dimensions for use with the above mentioned shoes in a shoe clamp arrangement, or without such a shoe in a foot clamping arrangement. This allows easy adaptation of many existing clamps using a simple, low cost foot, attachable to the clamp base using, as an example, screws or other known fastening techniques.
In accordance with another aspect of the present invention, there is provided a method of clamping a workpiece to a welding table or other work surface. The method includes attaching a shoe to the table or work surface, providing a clamp with a foot adapted to engage with the shoe and a clamping head, engaging the foot with the shoe, thereby securing the clamp to the table or work surface, and clamping the workpiece between the clamping head and the work surface.
It is accordingly a primary object of the present invention to provide an improved clamping apparatus and method for clamping a workpiece to a welding table or other work surface to thereby hold the workpiece in a fixed location with respect to the work surface during a welding operation.
It is another object of the present invention to provide a clamping apparatus of the type described above which is easily adaptable to many different clamping configurations.
It is yet another object of the present invention to provide a clamping apparatus of the type described above which is usable in the interior of the welding table or other work surface.
It is still another object of the present invention to provide a clamping apparatus of the type described above which reduces the costs associated with clamping workpieces for welding.
It is yet another object of the present invention to provide a clamping apparatus of the type described above which allows a relatively small number of clamps to be reconfigured in a short time to form a large number of different clamping configurations.
It is still yet another object of the present invention to provide a clamping apparatus of the type described above which allows storage of a welding table clamping configuration with the clamps removed.